USDA Forest Service

Pacific Southwest Research Station


Pacific Southwest Research Station
800 Buchanan Street
Albany, CA 94710-0011

(510) 559-6300

United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Research Topics Water and Watersheds

Study explores stream nitrogen concentrations

For the first time, a collaborative study [] has compared water quality trends in forested streams across the country that are largely undisturbed by land use or land cover changes. The study draws on 559 years of stream nitrate and 523 years of stream ammonium data from 22 streams in 7 experimental forests across the country. The study found that even near-pristine forested streams are subject to change.

Southern Sierra Critical Zone Observatory

The Kings River Experimental Watersheds hosts the Southern Sierra Critical Zone Observatory--a National Science Foundation effort to gain a better understanding of the zone of earth where "rock meets life." The critical zone extends from the tops of the trees to the groundwater and covers the entire earth where there is land. Dowload the video created by a UA Flandrau Science Center team to introduce the motivation and science involved in the National Critical Zone Observatory research program.

Kings River Experimental Watersheds (KREW)

KREW Data Collection

KREW stream discharge flume

In 2000 work began to build the KREW project infrastructure within the eight study watersheds. It took approximately two years to complete the initial construction which includes stream gauging stations, sediment ponds, and meteorology stations, as well as installation of a variety of field sensors and data collection equipment.

Data collection on KREW began in 2002 for the Providence Creek locations and in 2003 for the Bull Creek locations. Data collection has continued throughout the pre-treatment phase of the project, providing nearly 10 years worth of stream discharge, water and soil chemistry, and meteorological data for the eight study watersheds. The KREW project was designed from the outset to continue for at least 15 years, including several years of post-treatment data, and several seasons of data that span successive treatments.

Data Transmission Network (Radio Telemetry)

Yagi directional antennas for redirecting signals to the Foreest Service repeater. The Forest Service radio network is used to transmit data to the Forest office.
The USDA Forest Service has developed the capability to transmit data from standard data loggers at remote sites over the Forest Service VHF radio frequencies. The National Forest System provides a continuous radio network throughout the Sierra Nevada except in the National Parks. This capability was supported by the Kings River Experimental Watershed (KREW) on the Sierra National Forest and developed and implemented by Ted Etter ( of the USDA Forest Service Missoula Technology and Development Center. Initial costs ranged from $1,400 to $1,800 per location.

This system uses the existing infrastructure of Forest Service FM radios, broadcasting on the least-used channels. It allows data to be retrieved automatically from remote forest sites and is working with ISCO and Campbell Scientific data loggers. A modem from Teledesign Systems solved the problem of transmitting data over a channel designed for voice communication. This modem has several features that allow it to work with radios, such as generating a push-to-talk signal to key the transmitter. Dual-tone, multifrequency (DTMF) signals, like those used by touch-tone telephones, are used to communicate and help manage power consumption.

The telemetry system runs off of the same solar-powered system as the stream discharge stations and meteorology towers at each location. Depending on the terrain between the host station or repeater and the remote sites, the 5-watt Bendix-King radios can transmit signals up to 80.5 km (50 miles). The system has been in continuous operation on the KREW project since July 2002.

KREW Data Available Online

KREW meteorology station
Last Modified: Jun 21, 2013 08:28:18 PM